Marking chalk sharpener



July 4, 1961 w. MACKIE 2,990,811

MARKING CHALK SHARPENER Filed May 31, 1960 [w "UH '11) WE'JIi m Macln'e in. IL. JNVENTOR.

liqrl. BYg g Y United States Patent MARKING TCHALK. SHARPENER William Mackie, 3820 N. Gantenbein St., Portland, Oreg. Filed May 31,1960, Ser. No. 32,912

3 Claims; (CL- 120-94) Marking chalk is an essential tool in the tailoring craft and is used to delineate smooth. and clean lines which the tailor can easily follow during the fabrication or alteration of a garment. Tailors marking chalk is composed of an admixture ofchalk powder'and either waxorclay. The wax or clay with which common chalk powder is mixed is notonly the carrying agent for the common chalk but either of the carryingfagents adds the cohesiveness necessaryto eliminate the brittleness which ,is the well known characteristic of common chalk when compressed into chalk sticks. While the' admixture of wax with chalk powder or clay with chalk powder provides a firm type of tailors marking chalk, the wax or clay also adds the softness to the composition so essential to the makingof clear lines onthe'cloth which the tailor is marking forfab'rication or repair.

Tailors marking chalkcomposed of either of the mixtures hereinabove referred 'to' is fabricated into small rectangular blocks, beveledadjacent to their sidesto provide fine edges for impressing a thin lineon the material in process of being marked.

As previously stated, tailorsmarking chalk is firm but relatively soft and, therefore, its fine edges are quickly blunted. Consequently; the chalk. must be rebeveled periodically to reinstate the fine'edgesin order to make the desired smooth and thin" mark lines. This frequent shaving of the chalk to create the necessary bevel therein for providing the needed sharp edges has heretofore been accomplished by the use of any sharp instrument, such as a knife. However, the use of .a knife or similar sharp instrument for such purpose is notronly hazardous but, like the sharpening of a lead pencil with a knife, the edges are seldom evenly beveled and, as a consequence, neither sharp nor-smooth mark lines of uniform thickness can be made by the tailor and, furthermore, an exce ssive amount of markingchalk is wasted.

The primary-object of-my invention isto provide a device to quickly and efiiciently form uniform bevels in tailors marking chalk to provide sharp edges therein;

As a corollary to the foregoing, another object of my invention is to provide a device for shaving the sides of tailors marking chalk, which eliminates the hazards inherent in the use of a sharp instrument, such as a knife,

for such purposes as well as the lack of uniformity of bevels made by the use of such instruments.

A still further object of my invention is to provide a receptacle for the shavings removed from the tailors marking chalk during the beveling operation and thereby eliminate the mess incidental to the shaving process by other means.

Another object of my invention is to provide a device which is simple but efficient in operation, inexpensive to manufacture and extremely efficacious in maintaining sharp edges in tailors marking chalk.

Other objects and advantages and novel characteristics of my invention will become apparent and more readily understood from the detailed description which follows and from the accompanying drawings forming a part thereof, in which:

FIG. 1 is a side elevation of my invention showing the cutting member in two different positions;

FIG. 2 is a top plan view showing more fully the structural characteristics of my invention;

FIG. 3 is a perspective view of a fragmentary portion ice 2 of the movable cutting member embodying the principles of my invention; and e q t FIG. 4 is a perspective eleva-tional'vie'w of a piece of tailors marking chalk after being beveled by the device bent upon itself at an acute angle, as shown at 4, to form walls 5 and 6, is rigidly secured to the top ofcover 2.

-' in vertical relationship thereto.

Another metallic member 7 is also rigidly secured to the top of cover 2 in spaced parallel relation to Wall 5.

Thus, channelway 8 is formed therebetween into which marking chalk 9, as exemplified in FIG. 4, may be inserted whenever it appears necessary and desirable to rebevel the marking chalk. Member 7 has a minute portion of itself bent at approximately right angles to its remainingportion, as shown at 10, and having its edge 11 positioned to lie in the same vertical planeas wall 6. Edge.

, tion. as will shortly become apparent. A cut-out section 11 delimits the distance the marking chalk 9 can be inserted into channelway 8, and furthermore it, together with wall 6, act, in effect, as a fixed blade for the marking chalk sharpener embodying the principles of my inven- 12 is also formed in member 7 in order to aid in the insertion and removal of the marking chalk 9.

In addition to the inherent rigidity of wallsS and 6' and'member 7, because of their structural characteristics, there is, nevertheless, provided a bridge member 13 which is fixedly secured to the top of wall 5 and member 7 giving added reinforcement thereto.

It should be noted that wall 6 and edge 11 of member 7 are positioned in relation to opening 3 of cover 2 so that they are each partially juxtaposed over the opening and thereby confining a slight portion of the opening within channelway 8.

A blade supporting member 14, having an opening (not shown) adacent one of its ends, is pivotally secured to Wall 6, which also has a similar opening (not shown) equal in diameter to the opening formed in blade sup porting member 14. A threaded bolt 15 is inserted into these openings after their alignment. Coil spring 16 is fitted over said bolt and compressibly held thereon by butterfly nut 17. By this expedient the tension on coil spring '16 is transmitted to blade supporting member 14 causing it to be held against wall 6 in such relative tightness as may be determined and controlled by the compression applied upon coil spring 16 through the tightening or releasing of butterfly nut 17.

Cutter blade 18 depends from and may be an integral part of the blade supporting member 14. The length of cutter blade 18 is slightly greater than the maximum length of opening 3. Cutter blade '18 has its edge sharpened, as shown at 19. A handle 20 is formed at the other end of the blade supporting member 14 to more easily actuate the blade supporting member 14.

A third metallic member 21 extends vertically from the top of-cover '2 and is positioned adjacent to opening 3 in spaced relation to edge 11, each, however, being in a different lateral plane, thereby forming a space just wide enough for the blade supporting member 14 to fit snugly therein but without impairing its movement. In this manner the cutter blade 18 is prevented from deviating laterally from its coacting contact with edge 11 of the fixed blade and wall 6 during the beveling of the marking chalk regardless of the tautness of spring 16.

Modus Operandi In order to bevel and re-bevel marking chalk by the use of the invention herein described in detail, the marking chalk 9 is inserted into the channelway 8 formed between Wall and member 7 so that its side contacts edge '11 and protrudes slightly beyond the vertical plane in which edge 11 and wall 6 lie.

The blade supporting member 14, carrying cutter blade 18, is then brought down to engage the marking chalk 9 in a shearing action. The blade supporting member 14 is prevented from deviating from its shearing action not only by the compressed coil spring 16, which holds the knife against wall 6, but also by member 21.

When one face of the marking chalk 9 has been beveled and it is the desire to bevel the other side, marking chalk 9 is removed from channelway 8 and turned about, reinserted into channelway 8 as far as the edge 11 will permit it to go, and the shearing operation is repeated.

From the foregoing description, it is evident that there is provided a marking chalk sharpener which is admirably adaptable for the use particularly outlined in the foregoing specification and, although I have found from actual practice that the sharpener as shown and described is extremely efiicient in operation, it is quite possible that changes may be made in the details of construction and arrangement of parts which, nevertheless, will come within the scope of this invention, and, therefore, I do not wish to limit myself to the disclosure shown and described herein except as specified in the following claims, in which I claim:

1. A marking chalk sharpener comprising, a container, a cover for said container, a member vertically positioned on top of said cover and bent at an acute angle to form a pair of walls, a second member also vertically positioned on top of said cover in spaced relation to the first mentioned member forming a channelway between them being bent at approximately right angles so that one of its edges lies in the same vertical plane as one of the walls of the first mentioned member, an opening formed in the cover, a third member extending upwardly from the top of said cover adjacent to said opening and spaced slightly from the edge of the second mentioned member to prevent blade deviation, a blade supporting member, a cutter blade depending from said blade supporting memher, a bolt passing through one of the walls of the first mentioned member and near one end of the blade supporting member for pivotally mounting the blade supporting member, a coil spring fitted around the bolt and a nut for compressing said spring to thereby hold the blade supporting member snugly against said wall.

2. A marking chalk sharpener comprising, a container, a cover for said container, a member vertically positioned on top of said cover and bent at an acute angle to form a pair of walls, a second member also vertically positioned on top of said cover in spaced relation to the first mentioned member forming a channelway between them; being bent at approximately right angles thereto so that one of its edges lies in the same vertical plane as one of the walls of the first mentioned means, an opening formed in the cover, a third member extending upwardly from the top of said cover adjacent to said opening and spaced slightly from the edge of the second mentioned member to prevent blade deviation, a blade supporting member pivotally positioned to one of the walls of the first mentioned member, a cutter blade depending from said blade supporting member, and means associated with one of the walls of said first mentioned member and said blade supporting member for varying the tension between them.

3. A marking chalk sharpener comprising, a container, a cover for said container, a member vertically positioned on top of said cover and bent at an acute angle to form a pair of walls, a second member also vertically positioned on top of said cover in spaced relation to the first mentioned member forming a channelway between them being bent at approximately right angles thereto so that one of its edges lies in the same vertical plane as one of the walls of the first mentioned member, an opening formed in the cover, a third member extending upwardly from the top of said cover adjacent to said opening and spaced slightly from the edge of the second mentioned member to prevent blade deviation, a blade supporting member pivotally positioned to one of the walls of the first mentioned member, and a cutter blade depending from said blade supporting member.

References Cited in the file of this patent UNITED STATES PATENTS 

